Production of pigmented film



Oct. 15, 19 G. F. NADEAU ET AL PRODUCTION'OF PIGMENTED FILM Filed Oct.25, .1939

GALERMD EUG ENE R. CLEARAMN -WINV ITORS ATTORNEYS stares raonuc'rion ormomma rum Gale F. Nadeau and Eugene n. Clearman,

N. Y., asignors to Eastman Kodak Oomaster,

Rochpm, Rochester, N. 1., a corporation of New Application mm- 25,1939,.Serial No. 301,214

The present invention relates to the production of pigmented film, andmore particularly to the application of' a colored pigment. to a stripof acetate sheeting to render the transparent sheeting opaque for useas'lampshade'sand similar articles.

Inthemaking of suchfilm, onlyasingle color is used at one ia'me. Thepigment-is applied,

in the present invention, by nieans of an en- 0 graved intaglio. rollwhich is rotatably mounted in a pancontaining the solution which is tobe applied to the strip or'sheeting. -'1 'he surface of the roll isembossedso that there are a. plurality of very minute cups; which carrythe solution; the excess solution being scraped oil by means of a doctorblade. .The solution-in these various cups is then transferred orapplied uniformly to the strip by pressing the strip against .the cupsby means of a rubber pressure roll over 0 which the stripisfed.

Inthe production of pigmented film usingthe intaglio method of coating,serious were encountered due to the appearance of parallel lines orstreaks in the coated film strip. 5 These lines were clear lines causedby the lack of coverage or flow of the pigmenting ink, and appearedregardless of the adjustments made in the various coating conditions andseemed to be uncontrollable. It was at first thought that these 0 lineswere caused bytool marks or hardened streaksin the rubber-coatedpressure roll. Accordingly, a cloth moistened with. acetone was appliedto the presure roll in the hope that the rubber would be swollen andsomewhat softened.

5 It was found that with this treatment, the lines in the coated filmdisappeared in the area treated with the moistened cloth. It becameapparent that this was not the correct explanation of thedifiicultybecause it was later found that the cloth,

B after losing its solvent by evaporation, was equally eflective ineliminating these lines. In other words, a dry cloth was equallyas goodas one laden with solvent. As a-result of this discovery,

thedifiiculty was overcome by placing a stripof- 5 cloth, or similarmaterial, in'contact with the' 5 since the strip contacts the pressureroll on the 6 (Em (C!- 9 -5 side opposite the surface being coated. Thatthe phenomenon is static or electrical in nature is further shown by thefact that if one rubs the surface of the strip prior to the applicationof thepigment, such as at point G, Figs. 1 and 2, 5 with a brush oftinseLa large number of lines are produced wherever the tinsel contactsthe strip. Furthermore-the parallel line efiects are difierent onacetate and nitrate supports which, as is well known, have greatlydiflerent electrification P 709- 10 erties.

In addition to the above methods of eliminating the parallel linesorcoating streaks,-it has been found that a jet of-l'ow pressure steamdirected against the rubber-coated pressure roll previous to the pointof contact of the film strip there-'. with gives better results thaneither the dry or moistened strip. This fact tends to bear out thecontention that these clear parallel lines are caused by an electricalphenomenon. The steam 2o jet moistening the surface of the pressurerollimproves. the conductivity of its surface. The invention has,therefore, as its primary object the provision of'an arrangement whichinsures the production of a uniformly pigmented 2o Afurther object ofthe invention is the provision of an arrangement which prevents therepelling of the uniformly applied pigment solution and thus efiectivelyeliminates the presence '30 of clear streaks or lines in the finishedstrip.

A still fiirther object of the invention is the provision of anarrangement. of the class described which is simple in construction,inexpensive to manufacture, easy to apply to existing machines, andextremely effective and positive muse. r

To these and other ends, the invention resides in certain improvementsand' combinations of. parts all as will be hereinafter more fullydescribed, the novel features being pointed out in g the claims at theend of the specification.

Inthedrawing:- Fig. 1 is a side view of an apparatus for producingpigmented film. 1 4 Fig. 2- is an enlarged fragmentary view of a portionofthe apparatus illustrated in Fig. 1, and on a larger scale than thelatter, showing the relation thereto of a device constructed inaccordance with the present invention for eliminatm ing clear coatingstreaks in the finished pigmentedfilm; f

Fig. 3 is a partial view, on a larger scale than in Figs. 1 and 2, ofthe pigment applying roll and the pressure roiifor holding the filmstrip in position to receive the pigment from the applying roll; and

Fig. 4 is a view of a portion of a pigmented or coated sheet or film,showing the presence and relation of the clear streaks in the sheetprior 'to the application'of the device of the present invention.

Similar reference numerals throughout the various views indicate thesame parts.

Fig.1 of the drawing shows an apparatus for continuously applying asuitable colored pigment,

or inkto one surface of a strip of transparent acetatesheeting to renderthe latter opaque for The pigmented sheet or strip is then fed throughan elongated path to cure or dry the sheet, and

the finished opaque sheet is, then wound up on the wind-up roll l5.Certain of the above rolls are positively-driven to feed or draw thesheet through the apparatus. I

The embossed or engraved roll it is driven solely by the m'oving'stripH- and is rotatably mounted in a pan l6 containing a supply of suitablepigmenting' material 11. The surface of the roll It is formed withaplurality of minute cups or embosses I8 which, when the roll is rotatedthrough the material i1, become filled with the latter, as is wellknown. The excess material on the roll I4 is scraped therefrom by meansof a doctor blade l9 so that each cup i3 is filled just to the top orsurface of the cup, as shown at 20, Fig. 3. As the filled cups nowsuccessively engage the strip at 2i, the pigment in the cups istransferred or applied uniformly over the surface of the strip in theformof a plurality of small minute deposits, as shown at 221, Fig. 3. Inorder to insure proper transfer of the pigment to the sheet ii, thelatter is firmly held against the roll ll by the pressure roll l3, thesurface of which is coated with a' layer of rubber or other suitableelastic or resilient material to provide a fiexible backing for thestrip at the point of application of the pigment. The above describedapparatus may be of any standard or' well-known construction and doesnot constitute per se a part of the present invention. g

The various deposits 22 are uniformly applied and distributed over thesurface of the strip II; and were it not for the static effect, abovedescribed, each of these deposits would fiow or run out so as to mergewith the other deposits to provide a uniform coating over the entirefilmsurface. The presence of this static condition, however, causes, asfar as can be ascertained, a repelling of the sheet H to the variousdeposits 22 so that the latter do not tend to spread evenly but ratherseparate or segregate toform a plurality of. clear lines or tracks 26which extend along the film strip in substantially parallel relation, asclearly shown in Fig. 4'. Thus although the pigment is evenly anduniformly applied to the sheet II, the finished sheet does not have auniform coating or matte surface due to the presence of the lines oruncoated portions 26. Fur-v thermore, these clear lines are not uniformand may or maynotbe continuous. The presence of such lines therebyprevents the securing of a uniform matte surface which is highlydesirable for diifusing the light, and is considered a material defectby those in the trade and is therefore not acceptable thereto.

For these reasons, it is. highly desirable/that means be provided forneutralizing or overcoming this static effect so as to eliminate theformation of these troublesome lines and to secure a dry or moistenedwith a suitable volatile solvent such as acetone or alcohol. However,the method which best suits production methods is to spray low pressuresteam in a series of small Jets\29 against the rubber surface 23 of thepressure roller l3 previous tothe contact point 30 of the strip ll.These jets issue through small orifices 3! formed in a spray pipe 32which extends across the face of the roll I3, as shown in Fig. 2. Thespray pipe 32 is connected by means of a supply pipe 33to a suitablesource of low pressure steam, not-shown. A small pan 34 is positionedbelow the spray pipe 32 to catch any'dripping therefrom.

While either the pad or the spray pipe may be efi'ectively usedseparately, they may also be used together, or.in cooperating relationas shown in Figs. 1 and 2. In this arrangement, the pad 21 additionallyserves as a wiper to remove any excess moisture off the surface of theroll l3.

- This moisture thus removed by the pad 21 collects in a drain pan 35positioned below the pad,

as shown in Figs. 1 and 2. These drain pans 34' and 35 may then beconnected, by any suitable and well-known manner, to the point ofdisposal. The elimination of the clear lines in the finished strip bythe use of the steam jets tends to bear out the assumption that thelines are caused by an electrical phenomenon. We are unable, however,after considerable-investigation to definitely state whether the spraysimpress a static charge on or take such a charge 011 the strip. It isbelieved, however, that a static charge is impressed on the sheet toneutralize an opposite charge on the sheet. In any event the applicationof the steam jets to the pressure roll l3 definitely and positivelyeliminates the highly undesirable and unwanted lines 26 to provide a.

uniformly coated sheet having a matte surface which is readilyacceptable to the trade for use in lampshades and simflar articles.

It is thus apparent from the above description that the presentinvention provides a simple yet highly efiective arrangement forsecuring a uni form coated pigmented film strip. It is also apparentthat the apparatus is not only simple in construction, inexpensive tomanufacture, highly effective and positive in its results, but maybeeasily applied to existing machines.

, While one embodiment of the invention has been disclosed, it is to beunderstood that the 1. An apparatus for forming pigmented film by theintaglio method'comprising, incombination, an embossed application rollfor ap lying a pigmenting solution uniformly over the surface of a filmstrip, a solution pan in which said roll is rotatably mounted, apressure roll for feeding said strip over and for maintaining it insolution receiving contact with said application roll,and means applieddirectly to said pressure .roll for retaining the uniform distributionof said solution on said strip.

2. An apparatus for forming pigmented film by the intagio methodcomprising, in combination, an embossed application roll for applying apigmenting solution uniformly over the surface of a film strip, asolution pan in which said roll is rotatably mounted, a pressure rollfor feedingsaid strip over and for maintaining it in solution receivingcontact with said application roll, and means contacting said pressureroll for preventing the uniformly applied solution from separating toform clear lines extending longitudinally of said strip.

3. An apparatus for forming pigmented film by the intaglio methodcomprising, in combination, an embossed application roll for applying apigmenting solution uniformly over the surface of a film strip, asolution pan in which said roll is rotatably mounted, a pressure rollfor feeding said strip over and for maintaining it in solution receivingcontact with said application roll, and a strip arranged in wipingcontact with said roll for preventing the uniformly applied solutionfrom repelling and forming clear non-pigmented lines extendinglongitudinally of the strip.

4. An apparatus for forming pigmented film by the intaglio methodcomprising, in combination, an embossed application rollfor applying apigmenting solution uniformly over the surface of a film strip, asolution pan in which said roll is rotatably mounted, a pressure rollfor feeding said strip over and for maintaining it in solution receivingcontact with said application roll, and

- a fluid spray applied directly to said pressure roll,

said spray sewing to retain the uniform distribution of the solution onsaid strip to prevent the formation of clear lines in the strip.

5. An apparatus for forming pigmented film by the intaglio methodcomprising,- in combination, an embossed application roll for applying apigmenting solution uniformly over the surface of a film strip, asolution pan in which said roll is rotatably mounted, a pressure rollfor feeding said strip over and for maintaining it in solution receivingcontact with said application roll,'and a low pressure steam jetdirected against said pressure roll previous to the point of engagementof said strip therewith to prevent the separation of said solution onsaid strip and the formation of clear uncoated lines thereon.

6. An apparatus for forming pigmented film by the intaglio methodcomprising, in combination, an embossed application roll for applying apigmenting solution uniformly over the surface of a film strip, asolution pan in which said roll is rotatably mounted, a pressure rollfor feeding said strip over and for maintaining 'it in solutionreceiving contact with said application roll, a low pressure steam jetdirected against said pressure roll previous to the point of engagementof said strip therewith, and a wiping pad positioned intermediate saidjet and said point of engagement and contacting said pressure roll toremove the excess moisture therefrom, said jet and pad serving to retainthe uniform distribution of the solution on said strip and prevent theformation of clear uncoated lines in the finished coated strip.

. EUGENE R. CLEARMANJ GALE F. NADEAU.

